ocfs2: return ENOMEM when sb_getblk() fails

The only reason for sb_getblk() failing is if it can't allocate the
buffer_head.  So return ENOMEM instead when it fails.

[joseph.qi@huawei.com: ocfs2_symlink_get_block() and ocfs2_read_blocks_sync() and ocfs2_read_blocks() need the same change]
Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
index 5d18ad1..5b704c6 100644
--- a/fs/ocfs2/buffer_head_io.c
+++ b/fs/ocfs2/buffer_head_io.c
@@ -115,7 +115,7 @@
 		if (bhs[i] == NULL) {
 			bhs[i] = sb_getblk(osb->sb, block++);
 			if (bhs[i] == NULL) {
-				status = -EIO;
+				status = -ENOMEM;
 				mlog_errno(status);
 				goto bail;
 			}
@@ -214,7 +214,7 @@
 			bhs[i] = sb_getblk(sb, block++);
 			if (bhs[i] == NULL) {
 				ocfs2_metadata_cache_io_unlock(ci);
-				status = -EIO;
+				status = -ENOMEM;
 				mlog_errno(status);
 				goto bail;
 			}